Several types of humidifying devices are presently available for adding humidity and heat to a breathable gas stream supplied to patients utilizing ventilators or undergoing inhalation therapy. Also, because some such patients have reduced breathing capability, each breath may be supplied mechanically directly to the trachea. However, when the natural membranes in the nose and mouth are bypassed, artificial humidification is required.
Existing systems for humidifying a breathable gas stream have one or more disadvantages. For example, systems of the type shown in U.S. Pat. No. 4,110,419 require a large sterile reservoir, usually disposable, which is not only expensive but also contributes greatly to pressure compliance of the system. Thus, the pre-filled, sterile water reservoirs expand and contract with the ventilator pressure. Further, a supply of such reservoirs takes up a great deal of storage space. Sterile water is also expensive, it sells for as much as several dollars a quart. These and other disadvantages are overcome or at least substantially minimized by the present invention.